The extensive know-how of Bayer MaterialScience accumulated over several decades of research, permanent improvements and innovative product developments have resulted in a unique product portfolio, that is unmatched in the world and which offers solutions for numerous applications. World-famous DD-coatings based on Desmodur® and Desmophen® are still synonymous for high-quality polyurethane coating systems. Specific products, like raw materials for high solid coatings are listed in the high solid systems section.
Both, one- and two-component systems can be adjusted to suit any processing requirement and property profile of the finished coating system.
A general overview of different polyisocyanates and polyols:
(Pre-)reacted polyisocyanates – NCO-prepolymers
Prepolymers of the Desmodur® E range are reaction products of aromatic or aliphatic isocyanates and polyols. They react to long chain, highly resistant polymers resulting in solid products with specific adjustable final properties, such as strength or chemical resistance. Depending on their chemical structure they can be formulated to be either highly elastic or tough.
They represent an intermediate level between traditional polyurethane coating raw materials like MDI and the finished coatings produced with these raw materials. The prepolymers available at Bayer MaterialScience contain free isocyanate groups so they can be used as an NCO-component in formulations of solvent-free and water-free coating systems. This is done to modify the mechanical properties or the formulation behavior in a very controlled and precise way.
Prepolymers can be formulated as one-component and two-component systems. Used as one-component system the product reacts with moisture. As two-component system it is used the same way as a conventional polyisocyanate, which allows a slower, more controlled reaction of the system due to the partial (pre-)reaction of the isocyanate groups.
Desmocap® prepolymers are a special kind of prepolymers with blocked isocyanate groups, which minimizes product reactivity. This way either a fast reaction can be slowed down or the reaction temperature can be increased. These products can be used for flexible coatings for example, but for other applications as well. Our experts will gladly discuss your application and the suitable raw material.
Brochure: Prepolymers - Products & Applications
Brochure: Polyisocyanates - Products & Applications
